A pump module is disclosed in U.S. Pat. No. 5,392,750. This pump module includes a fuel filter for accommodating a filter element in a filter casing. The filter casing has a cylindrical shape or an arc-like shape. The fuel filter is disposed on an outer circumference of a fuel pump so that the fuel filter covers the fuel pump.
The pump module includes different parts in addition to the fuel pump and the filter. Therefore, the parts composing the pump module are required to be disposed compactly so that the pump module is minimized in size.
However, when a pressure regulator for regulating fuel pressure discharged from the fuel pump and/or a check valve for preventing the discharged fuel from flowing back to the fuel pump are mounted on the fuel pump, the length of the fuel pump in an axial direction may be lengthened in some cases where the pressure regulator and/or the check valve are mounted on a certain position. For example, the length of the pump module in a center axial direction of an outer circumference of the fuel pump (i.e., the axial direction) becomes longer, since the pressure regulator is disposed on the upside of the filter casing.
Moreover, when the pressure and a suction filter for eliminating contaminants in the fuel sucked by the fuel pump are mounted on the same side of the fuel pump in the axial direction, the pump module becomes larger. That is, the length of the pump module in the axial direction becomes longer, when the pressure regulator and the suction filter are separated each other in the axial direction so as not to contact each other.
Another pump module is disclosed in US-2001-0027779-A1. This pump module includes a pressure regulator disposed on an outer circumference of the fuel filter so that the length of fuel supply equipment in an axial direction is limited from increasing.
However, a pressure regulator is connected to a fuel supply passage for supplying fuel from a fuel filter to an engine. Especially, the fuel supply passage extends from the upper side of the fuel filter, and then the fuel supply passage is bent. The pressure regulator is connected to the passage after being bent. Here, the discharge pressure of the fuel pump is a fuel pressure regulated by the pressure regulator plus a pressure loss of the fuel flowing through the fuel supply passage extending to the pressure regulator. When the fuel supply passage is bent, the pressure loss increases. Therefore, the discharge pressure also increases. As a result, a size of a pump module becomes large for increasing the discharge pressure, and power consumption also increases.
Moreover, since the pressure regulator is disposed outside the outer circumference of the fuel filter through a clearance therebetween, the length of fuel supply equipment in the axial direction becomes longer. Further, since the fuel filter is disposed on the upper side of the fuel pump, the clearance between the bottom of the fuel filter and the fuel tank becomes much larger. Further, since a check valve is disposed on the upper side of the fuel filter and is disposed in the fuel supply passage, the entire length of the pump module in the axial direction becomes longer.